Scientists travel on the edge of the known world, exploring nature through observation, experimentation and repeated testing. Our building blocks are pieces of experimental evidence that are linked into coherent models of the universe . An essential part of the scientific process is the critical analysis of research results by scientists with expertise in the discipline. Because of this peer-review process, mistakes are supposed to be caught before they propagate in the literature.

Yet despite careful pre-publication scrutiny, some reports are later retracted or, worse, widely suspected to be erroneous but never corrected. One recent examination of 53 landmark medical studies found that further research was unable to replicate all but six of them.